The Mini DIN connector form is after the Japanese manufacturer Hoshiden KK (ホシデン 株式会社, ~ Kabushiki - gaisha ) named. It is one of the mini- DIN connections.
Mini DIN connectors are used for, among others, S -video connections (Y / C video ). Since only video signals are transmitted, the audio connection must be made via a separate cable (usually RCA).
The front connector has a diameter of 8.95 mm.
The picture shows the front view of a 4-pin S -Video jack:
Some computer graphics cards have a Mini DIN socket as an additional video signal output.